Influence of Different Fertility Management Practices on Productivity and Economics of Forage Soybean

India suffer a net deficiency of 35.6% green fodder, 10.95% dry crop residues and 44% concentrate feed ingredients (IGFRI Vision, 2050). In Jammu and Kashmir, 0.6 lakh ha is under cultivated fodder crops and faces a net deficit of 19% in fodder (Raja, 2013). The choice to grow cultivated fodder crops during kharif season in Kashmir is limited and are grown generally under rainfed conditions. The major kharif season fodder cereal crops are maize and sorghum and the legume fodder crops are cowpea and soybean. Among the legume fodder crops the soybean produced higher fodder yield as reported by Ummaisa, (2020). Therefore, to increase further the productivity of fodder soybean under rainfed conditions one of the option is to supply the nutrients in optimum level. The vermicompost was proven an important organic manure in supplying nutrients to agricultural crops and has attracted the researchers throughout the globe in past few decades. Proper rate of vermicompost along with chemical fertilizer is imperative to supply the nutrients to soybean fodder crop to get higher quality and production. Keeping these aspects in view the present investigation was undertaken to study influence of different rates of vermicompoast and chemical fertilizers on growth, fodder yield and quality of fodder soybean.

Field experiments were conducted during kharif 2019 and 2020 under rainfed condtions at Faculty of Agriculture Wadura, Sher-e-Kashmir University of Agricultural Science and technology Kashmir to find out the rate of vermicompost and N, P₂O₅, K₂O on fodder soybean. The study area falls in temperate climatic zone of Kashmir Valley. The soil of experimental field was clay loam in texture, high in organic carbon (2.3%), medium in available phosphorus (13.2 kg ha^-1), available potassium (327 kg ha^-1) and low in available nitrogen (128 kg ha^-1). The fertility levels were N, P₂O₅, K₂O kg/ha T₁ (0,0,0), T₂ (10, 30, 15), T₃ (20, 60, 30), T₄ (30, 90, 45 ) and T₅ (T2+0.1 ton/ha V.C), T₆ (T₃+ 0.1 ton/ha V.C), T₇ (T₄+0.1 tons/ha V.C) were assigned to RBD with three replication. ‘Shalimar soybean-1’ variety of soybean was sown at 30cm row to row spacing during both years of investigation. The experiment was conducted under rainfed conditions. The vermicompost as per the treatments was applied in the rows at the time of sowing. The nitrogen through urea, phosphorus through diammonium phosphate and potassium through muriate of potash as per treatments was applied as basal. For dry matter accumulation the samples were taken at the time of harvest and dried in shade, then oven dried at 60oC for 72 hours. Samples were weighed to a constant weight and dry matter was expressed as tonnes/ha. For economic analysis (benefit cost ratio) cost of inputs and price of outputs were calculated at prevailing market price.

Plant height and dry matter accumulation 
 
The fertility management practices induced significant difference in plant height and dry matter accumulation of soybean (Table 2). In general the growth characters (plant height and dry matter accumulation) of soybean were higher in 2019 compared to 2020. This is due to higher rainfall during the crop growth period in year 2019 compared to 2020 (Table 1). Taller plants were recorded with integrated approach (Chemical fertilizer + vermicompost) than to their corresponding chemical fertilizers alone. The data of two years showed that T₇ recorded significantly taller plants than T₅, T₄, T₃, T₂ and T₁, however was statistically at par to T₆. Further T₆ recorded significantly higher plant high than T₃, T₂ and T1. The mean dry matter accumulation was also observed higher in treatment T₇ (9.1 t/ha) followed by T₆ (8.8 t/ha) T₄ (8.3 t/ha), T₅ (8.2 t/ha), T₃ (8.1), T₂ (7.5 t/ha) and lowest in T₁ (6.4 t/ha). This is attributed to increased availability of nutrients with application vermicompost with chemical fertilizers. Also the increased rate of vermicompost and chemical fertilizer will have increased the availability of nutrients which have resulted in higher plant height and dry matter accumulation. Similar findings were reported by Chaudhani et al., (2019), Jagdeesh et al., (2018), Verma et al., (2017) and Maeshbabu et al., (2008).




 
Green fodder yield and economics
 
The green fodder yield of soybean was higher during 2019 compared to 2020. Moreover nearly similar trend was registered during both years (2019 and 2020) in all treatments (Table 3). Data presented in Table 2 revealed that the treatment T₇ recorded higher green fodder yield than T₅, T₃, T₂ and T₁ during both years (2019 and 2020). However T₇ registered marginally higher green fodder yield than T₆ and T₄. The higher growth characters (plant height and dry matter accumulation) in treatment T₇ were the reason for higher green fodder yield than rest of the treatments. Verma et al., (2017) also recorded higher biological yield of soybean in integrated fertility management. Furthermore, higher straw yield of soybean was reported by Jagdeesh et al., (2018) in treatments receiving integrated nutrient sources.



The treatment T₃ (N, P₂O₅, K₂O (20, 60, 30 kg/ha) recorded higher benefit cost ratio of 3.39 in 2019  and 2.81 in 2020  compared to other treatments. The reason for higher B:C in treatment T3 is due to lower cost of cultivation compared to T₇, T₆, T₅, T₄ and higher green fodder yield compared to T₂ and T₁.   

The present investigation revealed that application of N, P₂O₅, K₂O (30, 90, 45 kg/ha) along with 0.1 tons/ha vermicompost recoded higher green fodder productivity of soybean. However, the higher benefit cost ration was observed with application of N, P₂O₅, K₂O (20, 60, 30 kg/ha. Thus it may be concluded that for higher fodder production of soybean N, P₂O₅, K₂O (30, 90, 45 kg/ha) along with 1.0 tons/ha vermicompost should be applied. But, for higher economic returns only chemical fertilizers N, P₂O₅, K₂O (20, 60, 30 kg/ha should be applied.